Field of the Invention
The invention relates to field use spectroscopy equipment, and in particular, to adaptation of radiological and/or optical detection and/or identification equipment.
Description of the Related Art
A variety of instruments are used in the field to assist with hazard assessment and control. When users, whether it be a first responder or soldier, are called to respond to a situation, they frequently have some intelligence about the situation. In the case of a first responder, they have information from a call to emergency services where somebody may have explained what happened. In the case of a soldier, the infantry scouting a territory will identify something suspect and call in the appropriate personnel. When these users arrive on scene they frequently are under time constraints to prepare their tools and respond. In the case of the soldier, they may be getting shot at. In the case of the first responder, there may be victims that need rescuing or pressure to reopen an evacuated building. Making proper assessments with such instruments is only complicated by the increasing complexity of these tools. Accordingly, whether the responder is under a time constraint, or is not adequately familiar with the instrument, setting the various parameters can be a challenge.
Some of these instruments allow for configuration of the instrument to optimize performance. This optimization may be to have the instrument detect/identify or alarm on a specific kind of chemical, or list of chemicals. The optimization may be to improve performance, user safety or to have the instrument perform in accordance with the standard operating procedures (SOP). Current instruments that allow for user configuration offer a manual process that permits editing the settings one at a time. Manual configuration takes time, while the user is under time constraints, and therefore many times the instruments are not configured for optimal performance. This puts the users at risk and slows down the response.
What are needed are methods and apparatus for adapting or reconfiguring field instruments. Preferably, the solutions make use of field intelligence to assist a user with configuration control. Additionally, the solutions should be expedient and provide for improved performance of the instrumentation.
In addition, there is an ever increasing need for field-portable analyzers capable of reliably identifying unknown materials. Emergency response teams and law enforcement agencies frequently encounter unknown and potentially hazardous substances including toxic industrial chemicals (TICs), narcotics, explosives precursors, and improvised explosive devices (IEDs). In addition to these substances, conventional explosives, biological weapons, and chemical weapons continue to be threats for homeland security and military users. In the laboratory environment, mid-infrared and Raman spectroscopy have proven very effective for identifying such materials. Efforts to transition vibrational spectroscopy from a laboratory analytical technique to a field based tool have been on-going for more than a decade, and in recent years handheld spectrometers have been widely successful in a number of applications.
Field users of handheld spectrometers typically do not have extensive training in science or spectroscopy. As such, an important design consideration for such devices is to incorporate on-board intelligence capable of converting raw spectral data into answers. In qualitative applications, the question being asked by the end user frequently falls into one of three categories:
1) authentication: Is the measured test material consistent with genuine substance X?
2) screening: Does the measured test material appear to contain substance X?
3) identification: What material was measured?
The problem associated with authentication is quite bounded (e.g., “Is the measured spectrum consistent with a stored reference spectrum of material X?”). Authentication algorithms are typically used for raw material confirmation and anti-counterfeiting applications, and will not be considered further herein.
Screening algorithms evaluate whether at least a subset of features in an unknown measurement correspond to one or more specific substances of interest. Such algorithms require user input regarding the potential presence of materials (e.g., what test targets are being searched for, and what interferents are likely to be encountered). Thus, the screening application is also bounded, albeit not to the extent that authentication is. As such, screening algorithms are most attractive for scenarios where the instrument operator has knowledge regarding the potential presence of specific analytes.
Identification, or library searching, algorithms are configured to scour a library of known materials and determine whether the unknown spectrum is consistent with any stored responses from the database. While lower-end devices stop with pure material assessment, more sophisticated identification equipment incorporates automatic mixture analysis that is invoked if the unknown measurement does not match any library spectra. The mixture analysis is performed to determine whether a combination of stored responses explaining a significant portion of the measured data can be found. This is of great practical utility as samples encountered in the field are frequently impure. Identification algorithms are very flexible in the sense that they can identify an unknown material from many thousands of possible candidates; however, they do not incorporate information regarding the potential presence of specific analytes the same way that screening algorithms do. Thus, screening algorithms often provide enhanced detection capability which makes them attractive for specific applications such as chemical warfare agent or narcotics detection.
Portable analytical devices based on a range of technologies, such as infrared spectroscopy, Raman spectroscopy, X-ray fluorescence spectroscopy, mass spectrometry, etc. are now widely available and deployed globally. However, there is a continuing need for a spectrometer that combines a sensor adapted for providing Fourier transform infrared spectroscopy (FTIR) surveillance and a sensor for providing Raman spectroscopy surveillance.